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Supplementation of feed grade essential and non-essential amino acids to control levels in pigs fed reduced crude protein (RCP) diets meeting the SID His:Lys ratio requirement maintained growth performance and carcass composition in growing/finishing swine
Supplementation of feed grade essential and non-essential amino acids to control levels in pigs fed reduced crude protein (RCP) diets meeting the SID His:Lys ratio requirement maintained growth performance and carcass composition in growing/finishing swine
Tuesday, March 15, 2016
Grand Ballroom - Foyer (Community Choice Credit Union Convention Center)
Abstract Text: Previous research indicates aggressive feeding of AA to growing/finishing pigs results in reduced intake, gain, and fatter carcasses. This study investigated the role of dietary essential AA, nonessential AA, and electrolyte balance on these outcomes. PIC C29 × 380 pigs (n=196) were blocked by BW and treatments assigned to gender-balanced pens within block. Treatments were: 1) corn-soybean meal diets formulated to meet a constant Trp:Lys ratio (20) without feed grade Trp (PC); 2) RCP diets meeting the His:Lys ratio requirement (32) without added feed grade His but with feed grade indispensable AA added to control levels (Met+Cys:Lys, 60 to 65; Thr:Lys, 65 to 68; Trp:Lys, 20; Ile:Lys, 73 to 78; Val:Lys, 79 to 88; His:Lys, 45 to 51; EAA); 3) as 2 but with feed grade Glu and Gly (67:33) added to the same N in PC (NEAA), or 4) as 3 but with diets formulated using NaHCO3 to create the same dietary electrolyte balance as PC (dEB). All diets met the SID AA:Lys ratio requirement for each phase (23 to 41, 41 to 59, 59 to 82, 82 to 104, and 104 to 131 kg BW). Ractopamine (10 mg/kg) was fed during the last 3 wk. Pig BW and pen feed disappearance data were used to calculate ADG, ADFI, and G:F for each pen. HCW, LM and fat-depth (10th rib) were captured by Fat-O-Meter at slaughter. Pig growth performance and carcass composition were maintained by adding feed grade EAA to the RCP diet. ADG, ADFI, G:F and carcass characteristics did not respond to NEAA or NaHCO3 additions. These results suggest the reduced performance of growing/finishing pigs fed RCP diets formulated to meet the His:Lys requirement without using feed grade His in previous studies may be attributed to improper AA:Lys ratios and not from total N or dietary electrolyte balance.
Keywords: amino acid supplementation, reduced crude protein, growing/finishing swine
|
PC |
EAA |
NEAA |
dEB |
SEM |
P-value |
BW, kg |
131.9 |
131.6 |
130.8 |
130.6 |
2.3 |
0.97 |
ADG, kg/d |
0.89 |
0.88 |
0.88 |
0.88 |
0.02 |
0.96 |
ADFI, kg/d |
2.32 |
2.36 |
2.38 |
2.37 |
0.04 |
0.66 |
G:F |
0.31 |
0.30 |
0.30 |
0.31 |
0.01 |
0.98 |
HCW, kg |
96.90 |
95.98 |
95.59 |
94.58 |
1.53 |
0.71 |
FFL, % |
54.56 |
54.34 |
54.97 |
54.95 |
0.33 |
0.46 |
LM depth, mm |
67.43 |
67.07 |
68.53 |
68.63 |
1.33 |
0.70 |